1. Field of the Invention
The present invention relates to portable inhaler for propellant-free metered nebulization of a medicament preparation, having a pressure generator, and having an expulsion nozzle for delivering the nebulized medicament preparation as an aerosol. In particular, the invention relates to an inhaler that is constructed as a soft mist inhaler.
2. Description of Related Art
The present invention relates, in particular, to a so-called soft mist inhaler (SMI), i.e., an inhaler that produces a spray mist (aerosol) that spreads out only relatively slowly. Inhalers of this kind are, in particular, inhalers in which an aerosol is delivered at a speed of less than 2 m/s, preferably about 1.6 m/s or less and most preferably less than 1 m/s (in each case, measured at a distance of 10 cm from a expulsion nozzle) and/or wherein the delivery or nebulization of a dose—of preferably 10 to 50 μl of a medicament preparation—lasts longer than 0.7 s, particularly about 1 s or longer.
International Patent Application Publication WO 2005/079997 A1 and corresponding U.S. Pat. No. 7,571,722 disclose an inhaler which represents an SMI of the type to which present invention is directed. The known inhaler comprises, as the reservoir for a medicament preparation that is to be nebulized, an insertable rigid container having an inner bag containing the medicament preparation and a pressure generator with a drive spring for conveying and nebulizing the medicament preparation. Nebulization takes place without the use of propellant gas, namely by the force of the drive spring.
A problem with inhalers and SMIs in general is that the triggering of the nebulization of the medicament preparation and the intake of breath have to be coordinated. This may be difficult for the individual user. This tends to be a problem with SMIs on account of the relatively long nebulization time for each dose. Therefore, SMIs have not been used, up to now, for people with coordination problems, such as small children, or for animals, particularly large animals, such as horses.
International Patent Application Publication WO 2004/091704 A1 discloses an add-on device for the intermediate storage of a nebulized medicament preparation in a chamber. The add-on device is used in a so-called metered dose inhaler (MDI). An MDI comprises a pressurized container which contains the medicament preparation that is to be nebulized as well as a propellant gas. On actuation, the propellant gas causes the medicament preparation to be dispensed at comparatively high pressure and correspondingly high speed and with a high mass flow. Therefore, the delivery takes place over a very short time and lasts, in particular, for less than 0.4 s, usually for about 0.15-0.36 s.
The MDI's short duration of delivery is disadvantageous for inhalation as the intake of breath for inhalation normally takes considerably longer. The relatively high speed of more than 2 m/s, in many cases up to or over 8 m/s, at which the aerosol is usually delivered by an MDI, is also disadvantageous for inhaling into the lungs as the particles (droplets) of the aerosol are largely deposited on the walls of the user's throat when inhaled directly because of the high speed.
The known add-on device is intended for an MDI and serves to slow down the aerosol, particularly by increasing the flow distance. For this reason add-on devices of this kind are also known as spacers. Moreover, the add-on device serves for intermediate storage of the aerosol produced.
International Patent Application Publication WO 01/78818 A2 discloses an inhaler for the nose. The inhaler has a manually operable pump bottle and an adapter mounted thereon with a chamber for intermediate storage of an aerosol produced. The pump bottle is not an SMI in the sense of the present invention. Rather, the pump bottle has to be operated briefly and forcefully in order to achieve reasonable nebulization, so that the characteristics correspond to those of a uDI if, indeed, the pump bottle is able to produce an aerosol comprising the very small droplets that are desirable for inhalation into the lungs.
International Patent Application Publication WO 94/17753 A1 discloses an inhalation device for large animals, such as horses. The inhalation device comprises a uDI which delivers an aerosol into an add-on device having a tubular portion. The aerosol is sprayed in the longitudinal direction of the tubular portion. A soft adaptor which is designed to be introduced into a horse's nostril can be connected to the tubular portion. According to an alternative embodiment the inhalation device comprises a handle with an associated, manually operated, pivotable trigger element. When the trigger element is operated, the MDI is pushed in a linear manner, thereby opening a metering valve in the MDI and delivering aerosol into the tubular portion. A disadvantage of MDIs is that the nebulization uses propellant gas. Operation is also a problem in that the direction in which the trigger element is manually operated runs parallel to the longitudinal extent of the tubular portion or add-on device, so that the operator intuitively positions himself on the side opposite the delivery end of the add-on device; however, this is most disadvantageous for administering to a horse if the user has to hold the horse at the same time.